I have created my own `default.xml` file at below location

> /app/design/frontend/YOUR_COMPANY/YOUR_THEME/Magento_Theme/layout/default.xml

And I've added these lines into it:

    <referenceBlock name="catalog.topnav" remove="true"/>
    
    <referenceBlock name="store.menu">
        <block class="Magento\Theme\Block\Html\Topmenu" name="catalog.topnav.fix" template="Magento_Theme::html/topmenu.phtml" before="-"/>
    </referenceBlock>

It's running for me without problems with Varnish.

> Note: I've added **"catalog.topnav"** again without **TTL parameter** (just
> trying to remove or reset it doesn't work. It needs to be created
> again.)